1. Field of the Invention
The present invention relates to ultrasonic diagnostic equipment for guiding the insertion of a puncture probe or a treatment probe such as a PEIT probe, a radio frequency puncture probe and a microwave puncture probe into a target part.
2. Description of the Related Art
For treatment for a tumor such as a cancer of an internal organ, a puncture probe or a treatment probe is often inserted into a target part by ultrasonic guidance and the insertion is called ultrasonically guided puncture and others.
In case these probes are inserted, a guide mechanism for setting the insertion direction of the puncture probe for an ultrasonic probe of used ultrasonic diagnostic equipment is provided or a puncture adaptor is installed so that these probes are located in the diagnostic visual field of the ultrasonic diagnostic equipment for insertion. On the screen of the ultrasonic diagnostic equipment, the insertion path of the puncture probe preset in the guide mechanism or the puncture adaptor is displayed beforehand, is referred as an index, is located in a target part, and operation for the insertion of the puncture probe is executed.
Cells in the target part are extracted by the inserted puncture probe or cancer coagulation treatment in which ethanol is injected into the target part via the puncture probe is made. Recently, cancer cauterization treatment in which a microwave or a radio wave is radiated and the puncture probe for cauterization for cauterizing cancer is inserted may be also made (for example, refer to “Actual liver cancer radio frequency thermocoagulation therapy” compiled by Kokubu and Moriyasu and published by Nankodo in May, 2002).
As in insertion under ultrasonic guidance, a puncture probe is thin and the insertion direction is substantially parallel to an ultrasonic beam from ultrasonic diagnostic equipment at a small angle, a reflected wave signal having sufficient intensity by the probe cannot be acquired, and the stable and clear display on an ultrasonotomographic image of the position of the probe may be disabled.
In a process of insertion, the end of the puncture probe is bent in a direction having little resistance because of the resistance of internal organs and tissue, is inserted off from the width in a direction (also called a slice) of a tomographic image by an ultrasonic beam, and no puncture probe exists on an ultrasonotomographic layer. Further, as internal organs and tissue are moved by respiration, the puncture probe may be off an ultrasonic beam which is a field of view after insertion.
The invention for intensifying a reflected signal the sufficient intensity of which cannot be acquired (for example, refer to JP-A-63-290550) and the invention for adjusting an ultrasonic beam to a puncture probe off a field of view (for example, refer to JP-A-2000-107178) are proposed.
However, an ultrasonotomographic image by the puncture probe under the above-mentioned ultrasonic guidance cannot be sufficiently observed, operation for insertion into a target part is very difficult, and insufficiency in the stability of display and operability comes into question.
In treatment under ultrasonic guidance, positional relation among a tumor, a blood vessel, ambient internal organs and positional relation with the ends of probes are observed, moving probes in various positions on the surface of the body. Particularly, in cautery treatment by a radio wave and a microwave under ultrasonic guidance, progress is required to be observed during the treatment.
Besides, there is also a problem that the observation of a part at the back of a cauterized part from the position of a probe over a treated part is disabled because of the alteration of tissue by cauterization and generated bubbles. Therefore, a puncture adaptor is detached from a probe during treatment, a puncture probe and the probe are detached, and internal organs and tissue including the circumference of a target part are scanned by the probe and are often observed from a desired direction.
Therefore, in treatment under ultrasonic guidance, the three-dimensional grasping and verification of a target part and a treated part are important. However, in treatment using the ultrasonic diagnostic equipment depending upon only the above-mentioned guide mechanism of the conventional type puncture probe and the puncture adaptor, it comes into a large question that observation is enabled in only a direction in which the puncture probe related to the treatment is maintained in the slice width of an ultrasonic beam and the three-dimensional positional grasping is difficult.
Besides, as described above, to treat a tumor such as cancer of an internal organ, a puncture probe is often inserted into a target part of an examined body under the guidance of a tomographic image by ultrasonic diagnostic equipment. In such a case, a guide mechanism for setting the insertion direction of the puncture probe is provided to a probe of the used ultrasonic diagnostic equipment or a puncture adaptor is installed on the probe, and the puncture probe is inserted so that it is located in a diagnostic visual field by the ultrasonic diagnostic equipment. On the screen of the ultrasonic diagnostic equipment, the insertion path of the puncture probe which is preset in the guide mechanism and the puncture adaptor is displayed beforehand, is referred as an index, is located in a target part and operation for inserting the puncture probe is executed.
Cells in the target part are extracted by the inserted puncture probe and cancer coagulation treatment in which ethanol is injected into the target part via the puncture probe is made. Recently, to radiate a microwave and a radio wave and cauterize cancer, a puncture probe for cauterization is inserted and treatment for cancer may be made. Cautery by a radio wave is described in “Actual liver cancer radio frequency thermocoagulation therapy” compiled by Kokubu and Moriyasu and published by Nankodo in May, 2002 for example.
In case the puncture probe is inserted, viewing a tomographic image by ultrasonic diagnostic equipment, there is a problem that a reflected wave having sufficient intensity by the puncture probe cannot be acquired and the stable and clear display of the position of the probe in the ultrasonotomographic image is difficult because the puncture probe is thin, the insertion direction is substantially parallel to an ultrasonic beam at a small angle.
Besides, the end of the puncture probe is bent in a direction having little resistance of internal organs and tissue in a process of insertion, is off the width in a tomographic image direction (a slice direction) of an ultrasonic beam, no puncture probe exists on an ultrasonotomographic layer, the puncture probe is off the ultrasonic beam after insertion because internal organs and tissue are moved by respiration, and may be even invisible.
Then, some methods of making a puncture probe clear are known and ultrasonic diagnostic equipment for acquiring three-dimensional data is being developed. This type of equipment executes three-dimensional scanning by executing three-dimensional electronic ultrasonographic scanning or mechanically moving a probe and as three-dimensional volume data can be collected, a tomographic layer on which a puncture probe exists can be displayed by such equipment.
As described above, in three-dimensional ultrasonographic diagnostic equipment, predetermined volume is displayed at real time and designated plural tomographic layers are also displayed. However, a method of following an inserted puncture probe and displaying the end of the probe is not established yet.
As described in JP-A-2000-185041 for example, ultrasonic diagnostic equipment in which a signal generator is installed at the end of a puncture probe, a signal from this is received by at least three ultrasonic transducers and the end position of the puncture probe is estimated is known.
However, in this equipment, the signal generator is required to be provided to the end of the puncture probe, the puncture probe is required to be as thin as possible, and the signal generator is also required to be miniaturized. However, when the signal generator is miniaturized, signals received by the three ultrasonic transducers are reduced, and it is difficult to estimate the end position of the puncture probe.
Even if the end position of the puncture probe can be estimated in such a structure, only the current position of the end of the puncture probe can be actually detected. Prior to puncture, it is important where and in which direction puncture is made. However, in the above-mentioned conventional type ultrasonic diagnostic equipment, it is difficult to know a traveling direction of the end of the puncture probe which is the most important.
Besides, in case a puncture probe is inserted from an optimum position on the surface of the body without utilizing a puncture adaptor and the puncture adaptor has a degree of freedom in the inserted position and the inserted angle of the puncture probe, a path in which the puncture probe is inserted cannot be estimated. Besides, it cannot be estimated whether the puncture probe can reach a target part or not.
As described above, according to the conventional type ultrasonic diagnostic equipment for assisting puncture, the end position of the puncture probe cannot be precisely detected and a direction in which the puncture probe is inserted cannot be known.